1. Field of the Invention
The present invention generally relates to rock crushers, and more specifically to a cone rock crusher for crushing rocks into sized aggregate material, including an improved protective seal that prevents external contaminants from entering the crusher""s lubrication system.
2. Discussion of Prior Art
Crushers are used for reducing the size of rock. Cone are specifically designed to crush pre-sized material into small designated sizes of aggregate. As shown in FIG. 1 (prior art), a cone crusher 61 is cylindrical by design and requires a moving crushing head relative to a stationary bowl to accomplish its task. The head repetitively makes eccentric gyrating movements at a high rate of speed while simultaneously rotating slowly around a vertical axis. This latter movement is known as head-spin.
Head-spin is partly related to the contact, or more appropriately, the lack of contact on the stationary socket liner 2, which is mounted on top of the socket 3. The lubrication required for these movements is provided by pressurized oil rising through an oil passage 5 in the main shaft 4 and out through the head 1. Hydroplaning on a thin film of oil, the spherical underside 29 of the head 1 and the contouring mating surface of the socket liner 2 force the excess lubrication into an oil retaining ring 6. The oil retaining ring 6 is located on the upper outside of a socket 3 providing a return for the lubrication through drainage holes 7 within the socket 3 and back to a reservoir for re-circulation.
In the foregoing prior art design, the location between the movable head 1 and the stationary socket liner 2 is highly susceptible to contamination 8. (FIGS. 2, 3) Accordingly, the present invention is directed to this problem. The present invention provides an innovative seal to protect the lubricated bearing surfaces 12. The area modified is the location that houses the standard grease seal and water seal. (FIGS. 2, 3)
There are numerous manufacturers of cone crushers; all use different sealing methods within their machines. However, the cone crusher 61 of concern (FIGS. 1-3) utilizes these two methods. The standard seal utilizes a socket sealing ring 9 packed with grease. This design employs grease to capture and entrap dust, which then becomes embedded in this lubricant. The grease cavity 11 becomes saturated with entrapped particles which, with time, causes the erosion of the sealing unit. (FIG. 2)
The cone crusher water seal is designed to cause a pressure that flows through the seal area with a force of water to expel the dust out of the cavity. This non-contacting device utilizes a water chamber 10 bolted to the top of the socket 3. A quantity of pressurized water is introduced through a series of spray jets 23. The circular directional flow of continuous rising watered aids in removal of contaminants over a partition 24. Once the contaminants are on the other side, the contaminated water exits down drain outlets 25. This type of design has a non-contact counter-part welded in place around the underside of the head 1. The baffle ring 27 remains submerged within the rising water throughout.
This water seal concept at best is an effective seal for combating airborne contaminants. However, water contamination within the lubrication system is a regular occurrence in prior art designs. Uncontrollable factors such as fluctuating water pressure, humidity within the internal environment, erratic spray, hard water sediments, all hinder the effectiveness and efficiencies of prior art sealing systems, as exemplified by the system shown in FIG. 3.
As noted, the socket sealing ring 9 is packed with grease in an attempt to embed and entrap contaminants within the grease cavity 11 before reaching the internal lubricated bearing surfaces 12. The socket sealing ring 9 is held to place by keys 13 and key-ways 14 to prevent rotation while it is lifted off the socket base by a series of springs 15 and housing 16. The purpose of this lifting is to maintain permanent contact with its counterpart, the gyrating head sealing ring 17. There are inherent problems with the use of springs 25: they break inside of the housings 16, become stuck, and cause flotation to collapse. This ultimately creates a separation of the sealing mating surfaces 18, which then leads to contamination of the lubrication system. (FIG. 2) There is an additional problem in dealing with this area, where dirt and debris can be forced under the socket sealing ring 9. This contamination coming from the direction of the head skirt 20 eventually diminishes. The bottom edge of the socket sealing ring 22 is now exposed to the hydraulic-like forces of the debris which will cause not only oil contamination, but serious damage to both mating seals.
It would be desirable, therefore, to have an improved protective seal that prevents external contaminants from entering the crusher""s lubrication system.